WASHINGTON -LRB- CNN -RRB- -- Russian military aircraft flew just 500 feet over two U.S. Navy ships this week as the ships participated in a joint military exercise with South Korea in the Sea of Japan , according to U.S. military officials .

Two Russian Ilyushin IL-38 maritime patrol aircraft flew only 500 feet above a U.S. aircraft carrier .

On Monday , two Russian Ilyushin IL-38 maritime patrol aircraft , known as `` Mays , '' overflew the U.S. aircraft carrier Stennis while it was in international waters in the Sea of Japan .

The Russian aircraft flew about 500 feet over the ship , lower than other flights the Russians have made over U.S. ships in the past year .

The USS Stennis was about 80 miles east of Pohang , South Korea , participating in the joint military exercise when the flyover occurred .

On Tuesday , the USS Blue Ridge , a lead command and control ship , and the Stennis were overflown by two Russian `` Bear '' long-range bombers multiple times , according to U.S. military officials .

The Bears overflew the ships at about 2,000 feet , officials said .

U.S. military officials said that in both cases , U.S. Navy F/A -18 fighters met up with the Russian aircraft about 70 nautical miles from the U.S. ships and flew alongside them until they left the area .

On both days , U.S. aircraft tried contacting the Russian planes on international air frequency radio channels , but the Russian pilots did not respond , officials said .

The last time Russian planes flew over a U.S. Navy ship was February 2008 , when two Bears flew 2,000 feet over the aircraft carrier USS Nimitz south of Japan .

Russian long-range flights skirting U.S. or other nations ' boundaries have also been common over the last year .

Although the Pentagon does not often talk about the overflights , there is nothing illegal about the actions , and they are generally seen by the United States as nothing more than muscle-flexing by the Russian military .

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Two Russian planes flew within 500 feet of U.S. Navy aircraft carrier

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That flyover is lower than others Russians have made over U.S. ships this year

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U.S. aircraft tried contacting Russian planes , but pilots did n't respond

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U.S. fighter jets met up with Russian planes , flew with them until they left